Oracle Apex creating procedures - sql

Question

1) Create a procedure (PrintProc) that prints out "This is the Final Test".
2) Create a procedure (UpdateProc) that takes a 'student Id' and then updates his State to ‘New York’.
Pic student database
Pic of faculty database
For #1 is it
CREATE OR REPLACE
PROCEDURE PrintProc IS
BEGIN
DBMS_OUTPUT.PUT_LINE(’This is the Final Test’);
END;
To execute I did
begin
PrintProc;
end;
but I got an error
For #2 is it
CREATE OR REPLACE PROCEDURE UpdateProc
AS
BEGIN
Update Student
set s_state = 'New York'
where s_state = 'WI'
END;
and got this error Error at line 6: PL/SQL: ORA-00933: SQL command not properly ended
to execute it is it
Begin
UpdateProc;
end;
6) Create a procedure (PrintStudentsProc) that prints out a list of students who have been taught by Kim Cox.
CREATE OR REPLACE PROCEDURE PrintStudentsProc
AS
BEGIN
Select S.S_ID, F.F_ID
FROM Faculty F INNER JOIN STUDENT S ON F.F_ID = S.F_ID
WHERE F.F_ID = 1
END;
and I get this error Error at line 4: PLS-00428: an INTO clause is expected in this SELECT statement
Was about to make another topic about triggers but stackoverflow bugged out again and I can't post for -9 days cause I posted 6 recent(not even recent) questions.
5) Create a trigger (UpdateTrigger) that outputs a message saying "Student record is going to be updated” Before the Update Takes place on Student Table,
I did
CREATE OR REPLACE TRIGGER UpdateTriggers
BEFORE UPDATE ON StudentsInfo
BEGIN
DBMS_OUTPUT.PUT_LINE('Student record is going to be updated');
Update StudentsInfo Set StudentsUpdated = StudentsUpdated + 1;
End;
and how would I execute it?
begin
UpdateTriggers;
end;

Answer 1

1. Error in PrintProc
The error in following code:
begin
PrintProc;
end;
is caused by the invalid character ’ in DBMS_OUTPUT.PUT_LINE in PrintProc. Replace ’ with ', this should resolve that error.
DBMS_OUTPUT.PUT_LINE('This is the Final Test');
2. Error in UpdateProc
The error in UpdateProc is caused by missing semi-colon in update statement. Add semicolon like the following:
Update Student
set s_state = 'New York'
where s_state = 'WI';
3. Error in PrintStudentsProc
Regarding the error in PrintStudentsProc, you can't do plain select statement inside plsql block. You need to use cursor. Also, you are missing semi-colon in the following query:
Select S.S_ID, F.F_ID
FROM Faculty F INNER JOIN STUDENT S ON F.F_ID = S.F_ID
WHERE F.F_ID = 1;
Cursor for loop example:
CREATE OR REPLACE PROCEDURE PrintStudentsProc AS
BEGIN
FOR stud_rec IN (
Select S.S_ID SID, F.F_ID FID
FROM Faculty F INNER JOIN STUDENT S ON F.F_ID = S.F_ID
WHERE F.F_ID = 1)
LOOP
DBMS_OUTPUT.PUT_LINE(stud_rec.SID||', '||stud_rec.FID);
END LOOP;
END;
/
Have a look at other types of cursors here
4. Error in Trigger
For trigger, after creating the trigger you need to execute the statement which invokes the trigger. In your case it is before update, so you need to perform a update query on the table.
CREATE OR REPLACE TRIGGER update_trigger BEFORE
update ON StudentsInfo FOR EACH ROW
DECLARE
stud_updated int;
BEGIN
DBMS_OUTPUT.PUT_LINE('Student record is going to be updated');
select StudentsUpdated into stud_updated from StudentsInfo where s_id=:new.s_sid;
--increase the value
stud_updated := stud_updated+1;
Update StudentsInfo Set StudentsUpdated = :stud_updated;
DBMS_OUTPUT.PUT_LINE('Student updated count:'||stud_updated);
END;
/
The above trigger should be able to execute, whenever you perform an update on the StudentsInfo table.
Also, check this sqlfiddle